FLUVAL FX UVC IN-LINE CLARIFIER

Our first look at Fluval’s new offering to clear aquarium water.

Ultraviolet radiation has a (largely) long and successful history of controlling certain types of algae in ponds, and the same mechanisms can be easily applied to aquaria. That’s exactly what Fluval has done here, albeit with a modern twist.

Let me start by saying what this device isn’t. It is not a steriliser. If you’re eyeing up this kit with a view to reducing pathogen loads in a tank, you’re on the wrong track. Pathogen control requires a steriliser to have a particularly high UV light intensity, combined with a prolonged exposure—such devices are designed to maximise contact time and reduce the distance between pathogens and the light. What we have here is a clarifier. Working on a similar principle to a steriliser, it passes water from the aquarium around a UV bulb that emits a specific wavelength of ultraviolet light (in this case 253nm at peak) for a long enough time to cause the cells of free-floating algae to be damaged. In particular, exposure to 253nm UV light corrupts DNA, which can cause outright death of algae cells, or may cause them to become ‘sticky,’ clumping to each other and making it possible for mechanical filters (filter pads) to remove them from the water. Conveniently, UV also does the exact same thing to those rogue, nuisance bacteria that can occasionally cause a milky bloom in your tank. Well, no more…

Science lessons aside, the FX UVC In-Line Clarifier is a compact and tidy piece of kit that’s a breeze to use. Furthermore, despite the ‘FX’ in the name, it’s not strictly for Fluval FX canister use only—hosetails are included to reduce the 25mm,

FX-sized nozzles down to 16mm, meaning that out of the box it’s compatible with any external filter using that size hosing (including the Fluval 307/407 canisters). That said, there’s nothing stopping you from finding your own hosetails and stepping it down again to fit on smaller canisters.

Installation on an FX can either be directly to the outflow of the canister (an included 90° elbow facilitates this), or mounting either horizontally or vertically inside a cabinet.

For any other filter, it’s cabinet mounting only, and in all cases of mounting some additional hosing is required. The included mounting bracket is simply screwed into place (screws provided) and the UVC clicks into place. Pulling the top of the bracket towards you releases the UVC and you can pull it out again.

One important point at this stage is that the UVC needs to be connected to the outflow of whichever filter you’re using, and not the inflow. With the hoseclips provided, you connect everything up and then you’re ready to start blasting algae.

But what of bulb changes? Pond UVCs have a notorious history of needing replacement every six months or so, but the Fluval FX UVC incorporates a cold cathode fluorescent lamp which lasts a whole lot longer. With a lifespan of up to 20,000 hours, the Fluval clarifier can run 24 hours a day for around two years before the bulb needs replacing.

Bulb changing is beyond easy, but does require a crosshead screwdriver. Two screws retain the clear outer cover. Unfasten these, and you’ll be immediately able to extract and disconnect the bulb. Slip in a replacement, connect it, return the cover, and that’s your maintenance down for another two years. If you’ve installed it right, you’ll be able to see the reassuring purple glow on the end of the device. There’s a microswitch to ensure that the lamp only switches on when correctly fitted, so make sure that the end cover is tightly screwed back on. Which leads me to the closing caution. Never try to remove one of these bulbs, turn it on, and look at it. I had one customer do that with a pond UVC when I worked in Bristol and he required hospital treatment for the eye damage.

Owners of persistently cloudy tanks are going to love these. Aquascapers looking for that final polish of their water are going to love these. Marine keepers are going to love these. Heck, even owners of turtle tanks where bacterial blooms are commonplace are even going to love these. The price seems in the right ballpark for the unit, while the simplicity of installation and maintenance will make it user friendly for newcomers—who are most likely to experience cloudy tanks.

So easy to use.

Wish I could clean the quartz sleeve.